The Invacom feed normally comes from Invacom with no cap or cover and so the spiders can get in and lay their nests.
The result is that they block the signal. We fit a yellow cap on the end. This is better than a flat cover
as flat covers can be burnt through by the sun. Using a cap rather than a cover means that it is not at the
focal point and is much less likely to be burnt by the sun. The cap also has a small hole to stop the build up of condensation
and is exclusive to the Satellite Superstore. The Invacom feedhorn has a 23mm neck and a C120 flange It is made of
aluminium and has scalar rings. It is designed for prime focus dishes. The rings are adjustable on a screw thread
Please note that these important yellow caps are not available separately. Only with the feedhorn.
Adjustable F/D 0.32-0.43. You can adjust the rings on the treads to set the F/D to suit your dish.
See middle and right hand pictures below. Shown are different amounts of tread above the rings.

When the feedhorn is taken out of the box from the manufacturer, the rings are assembled the
wrong way round. (See left hand picture above). When unscrewing and turning over the rings and fitting correctly
it is VERY EASY for the aluminium threads to lock. If they lock they then strip when forced off.
We pre-assemble the rings the correct way round, coating the threads with petroleum jelly so that they cannot lock.To buy the feedhorn with a C120 flange LNB, scroll down.

Invacom feedhorn with yellow cap and Primesat feed support boss.
Shown above is an Invacom feedhorn fitted to a Primesat feed support boss. If you need a way of fitting this
feedhorn to your prime focus dish, you can use this support boss to bolt everything onto the ends of the 3 rods on
your dish. The support boss has two angles to choose from as far as interfacing with the rods on your dish. Usually the
shallower angle holes would be used with larger dishes. With this support boss, this feedhorn can be fitted any prime
focus dish that uses 3 arms although the bolts at the ends of the rods may need to be altered to suit the size
of the holes in the boss. Please note this prime focus feedhorn support boss" is available separately below.

The Invacom feedhorn normally comes from Invacom with no cap or cover and so the spiders can get in and make their
nests. The result is that they block the signal. We fit our own "Primesat yellow cap" on the end. This is better than a
flat cover as flat covers can be burnt through by the sun. Using a cap rather than a cover means that it is not at the
focal point and is much less likely to be burnt by the sun. This cap is included with all Invacom feedhorns and is
exclusive to the Satellite Superstore. Please note that these important yellow caps are not available separately.
Only with the feedhorn. The Invacom feedhorn has a 23mm neck and a C120 flange. It is made of aluminium and has
adjustable scalar rings. It is designed for prime focus dishes. The rings are adjusted on a screw thread. This feedhorn
has an adjustable F/D ratio from 0.32 to 0.43. You can adjust the scalar rings on the treads to set the F/D to suit
your dish. See middle and right hand pictures below. Shown are different amounts of tread above the rings.

When the feedhorn is taken out of the box from the manufacturer, the scalar rings are assembled the wrong way round.
(See left hand picture above). When unscrewing, turning over the rings, then fitting correctly it is VERY EASY for the
aluminium threads to lock. If they lock they then strip as the rings have to be forced off. We pre-assemble the rings
the correct way round on the feedhorn wave guide, coating the threads with petroleum jelly so that they cannot lock.
Included below are the Inverto and Invacom LNBs. The Invacom LNBs are very good but have a low output and don't
tend to work well with cable runs of over 30m. With less than 30m they are excellent. The Inverto LNB works well at any
length up to 70m if good cable is used. Please note that there is no significant difference between a
0.1db, 0.2dB or 0.3dB LNB. Read the "Getting more signal" question and answer advice section below.
To fit this feedhorn onto your prime focus dish you may need a "prime focus feedhorn support boss" as shown below.Discounted prices when you buy the feedhorn and LNB together.

The Invacom feedhorn normally comes from Invacom with no cap or cover and so the spiders can get in and make their
nests. The result is that they block the signal. We fit our own "Primesat yellow cap" on the end. This is better than a
flat cover as flat covers can be burnt through by the sun. Using a cap rather than a cover means that it is not at the
focal point and is much less likely to be burnt by the sun. This cap is included with all Invacom feedhorns and is
exclusive to the Satellite Superstore. Please note that these important yellow caps are not available separately.
Only with the feedhorn. The Invacom feedhorn has a 23mm neck and a C120 flange. It is made of aluminium and has
adjustable scalar rings. It is designed for prime focus dishes. The rings are adjusted on a screw thread. This feedhorn
has an adjustable F/D ratio from 0.32 to 0.43. You can adjust the scalar rings on the treads to set the F/D to suit
your dish. See middle and right hand pictures below. Shown are different amounts of tread above the rings.

When the feedhorn is taken out of the box from the manufacturer, the scalar rings are assembled the wrong way round.
(See left hand picture above). When unscrewing, turning over the rings, then fitting correctly it is VERY EASY for the
aluminium threads to lock. If they lock they then strip as the rings have to be forced off. We pre-assemble the rings
the correct way round on the feedhorn wave guide, coating the threads with petroleum jelly so that they cannot lock.
Included below are the Inverto and Invacom LNBs. The Invacom LNBs are very good but have a low output and don't
tend to work well with cable runs of over 30m. With less than 30m they are excellent. The Inverto LNB works well at any
length up to 70m if good cable is used. Please note that there is no significant difference between a
0.1db, 0.2dB or 0.3dB LNB. Read the "Getting more signal" question and answer advice section below.
To fit this feedhorn onto your prime focus dish you may need a "prime focus feedhorn support boss" as shown below.Discounted prices when you buy the feedhorn and LNB together.

The Invacom feedhorn normally comes from Invacom with no cap or cover and so the spiders can get in and make their
nests. The result is that they block the signal. We fit our own "Primesat yellow cap" on the end. This is better than a
flat cover as flat covers can be burnt through by the sun. Using a cap rather than a cover means that it is not at the
focal point and is much less likely to be burnt by the sun. This cap is included with all Invacom feedhorns and is
exclusive to the Satellite Superstore. Please note that these important yellow caps are not available separately.
Only with the feedhorn. The Invacom feedhorn has a 23mm neck and a C120 flange. It is made of aluminium and has
adjustable scalar rings. It is designed for prime focus dishes. The rings are adjusted on a screw thread. This feedhorn
has an adjustable F/D ratio from 0.32 to 0.43. You can adjust the scalar rings on the treads to set the F/D to suit
your dish. See middle and right hand pictures below. Shown are different amounts of tread above the rings.

When the feedhorn is taken out of the box from the manufacturer, the scalar rings are assembled the wrong way round.
(See left hand picture above). When unscrewing, turning over the rings, then fitting correctly it is VERY EASY for the
aluminium threads to lock. If they lock they then strip as the rings have to be forced off. We pre-assemble the rings
the correct way round on the feedhorn wave guide, coating the threads with petroleum jelly so that they cannot lock.
Included below are the Inverto and Invacom LNBs. The Invacom LNBs are very good but have a low output and don't
tend to work well with cable runs of over 30m. With less than 30m they are excellent. The Inverto LNB works well at any
length up to 70m if good cable is used. Please note that there is no significant difference between a
0.1db, 0.2dB or 0.3dB LNB. Read the "Getting more signal" question and answer advice section below.
To fit this feedhorn onto your prime focus dish you may need a "prime focus feedhorn support boss" as shown below.Discounted prices when you buy the feedhorn and LNB together.

Please note, Inverto and Invacom have both discontinued their range
of c120 quatro LNBs in Nov. 2017. All stock has now been sold.
See below for the new range of Primesat Platinum c120 quatro LNBs.

Invacom feedhorn with quatro Primesat
Platinum quatro C120 LNB

The Invacom feedhorn normally comes from Invacom with no cap or cover and so the spiders can get in and make their
nests. The result is that they block the signal. We fit our own "Primesat yellow cap" on the end. This is better than a
flat cover as flat covers can be burnt through by the sun. Using a cap rather than a cover means that it is not at the
focal point and is much less likely to be burnt by the sun. This cap is included with all Invacom feedhorns and is
exclusive to the Satellite Superstore. Please note that these important yellow caps are not available separately.
Only with the feedhorn. The Invacom feedhorn has a 23mm neck and a C120 flange. It is made of aluminium and has
adjustable scalar rings. It is designed for prime focus dishes. The rings are adjusted on a screw thread. This feedhorn
has an adjustable F/D ratio from 0.32 to 0.43. You can adjust the scalar rings on the treads to set the F/D to suit
your dish. See middle and right hand pictures below. Shown are different amounts of tread above the rings.

When the feedhorn is taken out of the box from the manufacturer, the scalar rings are assembled the wrong way round.
(See left hand picture above). When unscrewing, turning over the rings, then fitting correctly it is VERY EASY for the
aluminium threads to lock. If they lock they then strip as the rings have to be forced off. We pre-assemble the rings
the correct way round on the feedhorn wave guide, coating the threads with petroleum jelly so that they cannot lock.
Included below is a Primesat Platinum c120 flange LNB. The Primesat LNBs are very good and works well at any cable
length up to 70m if good cable is used. To fit this feedhorn onto your prime focus dish you may need a
"prime focus feedhorn support boss" as shown below.
More information on the Primesat c120 LNB.Discounted prices when you buy the feedhorn and LNB together.

Primesat feedhorn support boss - see above left (feedhorn not included).
Shown above right is an Invacom feedhorn (not included) fitted to a Primesat feed support boss. If you need a way of
fitting a feedhorn to your prime focus dish, you can use this support boss to bolt everything to the ends of the
3 rods onto your dish. The support boss has two angles to choose from as far as interfacing with the rods on your dish.
Usually the shallower angle holes would be used with larger dishes. With this support boss, this feedhorn can be
fitted any prime focus dish that uses 3 arms although the bolts at the ends of the rods may need to be altered
to suit the size of the holes in the boss.

A 1.2m prime focus dish is shown above.
This type of dish is circular NOT oval. It has 3 feed support arms (some use 4 arms) and the 3 arms
converge in the centre. Each arm is 120 degrees apart. The feedhorn uses concentric scalar rings.
The concentric scalar rings reduce noise and improve signal to noise ratio with prime focus dishes.
An offset dish (See below) is oval and is higher than it is wide (some are wider than they are high).
They use either one feed support arm (at the bottom of the dish - see bottom left hand picture) or 3
feed support arms (again all in the bottom 1/2 of the dish - see bottom right hand picture).
Many offset dishes use a standard 40mm clamp LNB but some more expensive specialised offset dishes
also use a feedhorn If a feedhorn is used, a c120 flange LNB is bolted to it.

As a general rule the two types of dishes are simply two ways of doing the same job, however, an offset
dish, if well engineered, usually has significantly more gain than the prime focus dish. It is never
really that simple. It is true that petalised offset dishes usually have poor gain but a one-piece
well engineered prime focus dish can be better than a poorly engineered offset dish and some very
good prime focus dishes can have the same gain as a good offset dish of the same size.
As usual you get what you pay for. Cheap prime focus petalised dishes are to be
avoided and we don't sell them.
Prime focus dishes probably look better than offset dishes as they point upwards.

Scroll down for advice.

Questions -

How much difference do low noise LNBs make and why do
some LNBs have a C120 flange and a feedhorn? Is there much difference
between the efficiency of different makes and types of dish?

AND,

How can I get more signal from my dish? Would a better LNB
help or a more sensitive receiver?

AND,

Problems with signal through trees.

AND,

Why does my lower noise LNB produce less signal?

Answers -

Dish size is everything.

Dish size is everything. LNBs only have a very very very very .... small effect as does receiver
sensitivity. Dish size is everything! Going from a 0.9dB to a 0.1dB does not have the effect of
5mm of dish diameter! and then the lower noise LNB will only help in good weather, virtually no
effect in bad weather. Bigger dishes provide more signal in all weathers. BUT .. if the dish size
cannot be increased for any reason, the lower noise LNB can help a small amount and it MIGHT be
just enough to pull in a difficult to receive channel that was just coming in but maybe pixilation or
freezing (a common fault caused usually by lack of signal) was a problem and may be stopped.
0.1dB LNBs! To achieve 0.1dBs over a significant frequency range, manufacturers would need super
cooling to slow the electrons down! Simply not possible at normal temperatures in the UK. It may
well be the case that the new 0.1dB LNBs have the lowest noise figures. They are very good LNBs.
Possibly even be the best, but they really can't be as low as 0.1dB or 0.2dB over any kind of
useful frequency range if at all. Some of us are getting old! I can still remember - when I was a
kid - back in the late 1950s early 1960s - not sure when - being told you could get a great picture
on the TV with an aerial shaped like a PLANT POT that could be stood on top of the TV.
(even with a plastic plant inside it!) We all now know that what was really needed was a decent
sized aerial on the roof (and preferably not in the loft - which can produce reflections!
Many people would like technology without wires in sealed boxes (like my wife, she will insist
on having the stuff in cabinets with doors on. This is better known as an cooking the technology
in an oven as it stops ventilation and creates a fire risks).
Many also want the smallest possible dish so the question is - "find an alternative solution to
getting more signal" BUT ... no matter how much people might want to .....YOU CAN'T CHANGE THE LAWS OF PHYSICS! "Dish size is everything." It is a question that we hear
every day and sometimes customer think that if they ask the question in 4 or 5 different ways, they
will eventually hear a different answer. To repeat - Dish size is everything! Dish size is everything!

Dish efficiency.

This can be important. Especially among large dishes. The Andrews (Channel Master) 1.8m and 2.4m have a
very high gain due to very good design. Offset should be more efficient than prime focus if it is a
specialist well designed dish (not always true with smaller mass produced dishes). Webbed resin type plastic
is a perfect shape from leaving the factory to arriving at the customer. Metal petalised prime focus dishes
can be warped when they are new due to bad assembly or damage and tend to be very in-efficient.
See the Andrews (Channel Master) dishes on the fixed dishes page and motorised dishes page
for very high quality resin type perfect shaped dish products.
Matched feedhorns can pull in more signal than better LNBs. See below.

Feedhorns.

A normal 40 mm clamp LNB has an integral offset feedhorn for offset dishes like the
Triax dishes (see offset dishes on the dishes page )
A Prime focus dish like the Unicorn (see an example of focus dishes on the C Band LNBs page
A Prime focus dish should have its own feedhorn with "scalar rings" on one side and a
C120 flange on the other. See the prime focus feedhorns shown on the Feedhorns
page
i.e. the Universal Feed and the Invacom feed, here you should use the C120 flange LNB which fits the Prime
Focus feed. If a prime focus dish does not have a proper feedhorn then it should have one.
The scalar rings on a prime focus feedhorn are a very important part of the design.
The feedhorn should really be designed and made by the dish manufacturer for a perfect match
but if this is not known or possible, fit a the "universal feedhorn" on the feedhorns
page This will be the
best match possible. This kit only requires you to have the 3 feed support arms. The boss etc
is all in the kit.The Andrews (Channel Master) offset feedhorn.
We have supplied this feed to customers who have found it made a worthwhile improvement.
If an LNB feed is not a perfect match, like a standard 40mm clamp LNB, it may illuminate (say) 1.1m
of a 1.2m dish. (less signal) OR, It may (try to) illuminate 1.3m of dish. This will cause infrared
(noise) to be picked up round the edges. The result is a poor signal to noise ratio. (poor picture)
Feedback from customers suggest that the matched feed on a Channel Master 1.2 as far west as Belfast
brought in all of Sirius. Before it was fitted this was not possible. More feedback suggested it can
make a difference in southern Spain For Sky TV and the BBC on an Andrews 1.8m dish and on the 2.4m Andrews
(Channel Master) dish from the Spanish offshore islands.

Receiver sensitivity.

This has only a very small effect on the signal. Most CI and free to air receivers are sensitive anyway.
Some Sky digiboxes, however, do not have particularly sensitive tuners. Not a problem in the UK but
in Spain a sensitive satellite receiver can help a little.

More information about LNBs.

An LNB is the box of electronics on the end of the dish boom arm. It acts like a aerial masthead
amplifier. The signal (microwaves) reflect off the dish and into the feedhorn to the LNB.
Here it is amplified and the frequency is lowered. The lower the noise figure the better.
i.e. in simple terms, it pulls in the signal better. The signal is then sent down the coaxial cable to the
satellite receiver. Quality digital cable should be used. (not CT100 or RG6)
See our Satellite Cable for good digital cable. Also see Twin satellite Cable See 4 LNB cable below.
A universal LNB covers the KU band from 10700 to 12750Ghz with LO frequencies of 9750 and 10600.
There are Single LNBs,Twin
LNBs,Quad LNBs,Octo
LNBs and Quatro LNBs. Single have one output,
twin - two outputs, quad - 4 outputs and Octo - 8 outputs. All outputs are the same and are equivalent to
a single LNB. A twin LNB could be used for two single tuner satellite receivers or a twin tuner satellite receiver
Quatro LNBs have 4 outputs and they are all different. Quatro LNBs can only be used with multiswitches.
There are also 40mm clamp LNBs and C120 LNBs. This refers to the way they fit on a dish. A 40mm LNB has an
integral offset feedhorn and fits to the most common types of offset dishes.
C120 flange LNBs fit on a separate feedhorn and could be used on either offset or prime focus dishes.
They are usually used on specialist high quality dishes.
Both 40mm and C120 LNBs could have single, twin, quad or quatro outputs.
At the moment only 40mm LNBs have octo outputs.
Using a quatro LNB and a multiswitch it is possible to have many more outputs. Even 32 outputs or larger.
A Sky mini dish LNB uses a fixing that is none standard and a tongue fits into the end of the boom
arm

To conclude,

"Dish area is everything". Other small gains are possible but they are small.
Large increases in signal are possible in all weathers with bigger dishes.
A large gain can be made if a dish is found to be warped and then corrected.
More efficient dishes provide gains but not as much as manufacturers claim they do.
When a manufacturer says their 50cm dish is equivalent to other 60 or 80cm dishes,
This is marketing not science! (Putting it another way this is sales jargon for lying!)
A more efficient dish might have the effect of being as good as a dish 1.0cm diameter bigger
but not the sort of silly claims some manufacturers (or dealers) make.
Small gains are possible with matched feedhorns
Very small gains might be possible with better LNBs or more sensitive tuners but they may be
too small to be significant

If trees are in the way, the signal will not get through them, however, if they are on the fringe
of being in the way - maybe only a thin band of branches and leaves with a good proportion of the
signal actually getting through, a bigger dish will collect more signal and compensate for the problem.

Better LNBs can producing less signal.

This is a very common question.
The important point here is that only a higher signal to noise ratio matters not the total signal level.
The total signal level is shown on a satellite meter and is NOT relevant. Meters do NOT measure the
quality of an LNB as meters are NOT measuring signal to noise ratio (over a frequency band.)
A high (signal) output LNB is good for driving a signal down a long cable (e.g. over 40m)
But a high signal to noise ratio pulls in weaker signals.
Remember - if you are looking at the meter reading in your receiver THAT TELLS YOU NOTHING AT ALL
as far as this particular question is concerned.
It only shows you the total signal and not the difference between the signal and the noise.
A poor 0.9dB (but high output) LNB on a short cable (not much attenuation) can produce
a large reading on a signal strength meter than a low output 0.1dB LNB.
A low output LNB (like an excellent 0.3dB Invacom) on a longer cable can show a low
signal on a signal strength meter.
So what?!! it has nothing at all to do with the ability to pull in a weak channel - nothing at all.
At a technical level, if you draw a graph with a horizontal line representing the signal
and a lower horizontal line representing the noise, the meter is simply showing the level of the
top line. With a high output LNB on a short cable the two lines move up equally BUT the height
difference between the two lines does not alter. With a low output LNB on a longer cable the two lines
move down equally BUT the height difference between them again does not alter. With a lower noise
LNB or bigger dish the height difference between the two lines INCREASES - we say there
is a better SIGNAL TO NOISE RATIO. A signal strength meter does not measure this parameter.
Anyone who says it does, probably has a no technical background in electronics. It is like
saying that the signal to noise ratio of a Hi Fi system is better if you turn up the volume.
Your ears would be equivalent to the signal strength meter and this statement would be
total rubbish as well - but it is an interesting, accurate analogy.
The only test is to check out the capability of pulling in weak channels - do not use the meter
for comparing LNBs. The meter is designed to help to locate the satellite accurately and
not to test the LNB.

High Quality Twin Cable

Please note we do not sell the thin twin "Shotgun" cable. We only sell higher quality 7mm twin cable.

Ideal for twin tuner receivers, Sky +, Sky HD. For twin LNBs or two LNBs.
Order this cable on the satellite cable page.

4 LNB cable.

This cable could be used with quad LNBs, quatro LNBs, two twin LNBs, or 4 single LNBs.
Each cable is 7mm as so it fits our screw on F connectors and our compression fit F connectors.
Order this cable on the satellite cable page.

C Band offset feedhorn with
feed support boss.

This is an offset feedhorn and it will allow C Band voltage switching LNBs to be fitted to offset dishes.
The feed support boss is designed to take a 60mm LNB neck. Most C Band LNBs use a
60mm neck. The boss can be fitted to the satellite dish feed support arm.
It may be necessary to modify the end of the dish arm to fit this boss. One bolt is used
to fit this feed support boss to the arm and so a hole may need to be drilled through the arm.
If there is a single arm, or side support arms are connected to the main arm further down
the arm and there is only a single arm tube at the end, (e.g. a Gibertini dish) fitting this
support boss should be easy. If three arms all converge right at the end (e.g. a Raven dish),
the modification would be more difficult.

This site includes many products that are exclusive to the Satellite Superstore.
The site contains -
• Products that we manufacture (e.g. We have manufactured heavy duty wall mounts and ground stands since 1991).
• Selected products which have our own Primesat brand name and have been prepared to our specifications.
• Selected products where we have been appointed the authorised UK or European distributor by the manufacturer.www.primesat.eu is an information site. Here you will find full specifications and many detailed pictures.
To buy any of these products, simply order them on this web site.

Also see www.rewindmuseum.com. A Museum of vintage consumer electronics.
Vintage reel to reel video recorders. Vintage VHS and Betamax VCRs. Vintage video cameras. Vintage
Laser Disc. Vintage Computers. Old telephones. Old brick mobile phones. Vintage Hi Fi, Old reel
to reel audio and early audio cassette decks. Including, the history time line of vintage
consumer electronics ... and much more .....

It is well worth a visit.
Only The Satellite Superstore brings you
great products, advice and it's own museum.